Transcript for Secretary of State John Kerry Urges Critical Ally to Calm Tensions

Secretary of state john kerry asking china to use its muscle at this critical moment with north korea. A powerful show of military might today while in south korea a very different kind of show. Bob woodruff from seoul again tonight. Reporter: Secretary of state john kerry visited north korea's only ally today, asking chinese leaders to calm their neighbor down. Two great powers, china and the united states could work effectively to solve the problem. Reporter: China and the u.S. Vowed to persuade north korea to give up its nuclear weapons program but china has not pressured north korea nearly as hard as the u.S. Has. Refugees pouring over borders with repercussions. On the streets of pyongyang today they were honoring the 100th birthday of kim ill-sung. It could be used as an excuse to conduct a missile test that has the region and the world on edge. In seoul today a completely different picture, 50,000 fans celebrated with the musician psy who became known for his hit gangnum style. Reporter: The people in that he released his follow up today called gentleman. what is going on in north korea. It's just that this generation has lived through times of military confrontations for their entire lives.

This transcript has been automatically generated and may not be 100% accurate.

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